Coated mandrel for carton forming machine

ABSTRACT

The mandrels in a carton forming machine are coated with a layer of a normally solid poly(arylene sulfide). The poly(phenylene sulfide) coated mandrels are particularly advantageous for use in carton forming machines wherein the mandrels are rotated about a common axis in that light weight metals such as aluminum can be utilized to form the mandrel rather than steel, thereby permitting a higher rate of rotation and greater production of cartons.

United States Patent [1 1 Coburn et al.

[4 1 Oct. 7, 1975 COATED MANDREL FOR CARTON FORMING MACHINE Inventors: Leslie 0. Cohurn; Silvio T.

Fariaglia, both of Fulton, N.Y.

Assignee: Phillips Petroleum Company, Bartlesville, Okla.

Filed: I Sept. 7, 1973 Appl. No.: 395,028

US. Cl 93/392; 93/44.1 R; 156/443; 156/567; 156/580 Int. Cl. 83113 13/02; B3lB 17/26 Field of Search 156/215, 218, 289, 458,

156/537, 567, 568, 443, 580; 93/362, 39 R, 39 C, 39.2, 39.3, 44.1 R; 117/132 B, 132 CF, 161 UZ References Cited UNITED STATES PATENTS 12/1955 Barnes et a1. 93/392 3,354,129 1l/1967 Edmonds, Jr. et a1 260/79 3,492,125 l/1970 Ray 117/127 3,622,376 1 1/1971 Tieszen et al. 117/132 B 3,629,028 12/1971 McLarty et al..... 156/289 3,652,327 3/1972 Hill, Jr. et al 117/123 D 3,728,313 4/1973 Hill, Jr. et a1. 117/16] R 3,779,836 12/1973 Henry et al. 156/218 Primary Examiner-Charles E. Van Horn Assistant Examiner-Basil J. Lewris [5 7] ABSTRACT The mandrels in a carton forming machine are coated with a layer of a normally solid poly(arylene sulfide). The poly(phenylene sulfide) coated mandrels are particularly advantageous for use in carton forming machines wherein the mandrels are rotated about a common axis in that light weight metals such as aluminum can be utilized to form the mandrel rather than steel, thereby permitting a higher rate of rotation and greater production of cartons.

7 Claims, 3 Drawing Figures US. Patent "Oct.7,1975 Sheetl0f2, 3,910,169

was

US. Patent (M11975 sh etzofz 3,910,169

FIG. 3

COATED MANDREL FOR CARTON FORIVIING MACHINE The invention relates to a carton forming machine having a mandrel coated with a normally solid poly- (arylene sulfide).

Tubular cartons are frequently formed from flat blanks by wrapping each blank about a mandrel and sealing the overlapping margins. Portions of the blank can be folded to form a bottom structure or a separate bottom blank can be employed to form a sealed bottom on the convoluted tube. Difficulties are sometimes encountered in stripping the formed tubular container from the mandrel due to frictional resistance between the forming surface of the mandrel and the interior surface of the container. It is a common practice to employ a polished steel mandrel to provide a lower frictional resistance than would be achieved with metals such as aluminum. In many of the carton forming machines employing more than one mandrel, it is customary to position the mandrels on a turret and to rotate the mandrels about the axis of the turret to move the mandrels from station to station. The use of steel mandrels on these turrets limits the practical rotative speed of the turret due to the weight of the mandrels.

In accordance with the present invention the utilization of a normally solid poly(arylene sulfide) coating on the mandrel reduces the frictional resistance between the mandrel and the container. The utilization of a normally solid poly(arylene sulfide) coating on a light weight metal such as aluminum permits the attainment of a higher production rate for carton forming machines employing a plurality of mandrels on a turret as well as providing reduced frictional resistance between the mandrel and the container.

Accordingly it is an object of the present invention to provide an improved mandrel for a carton forming machine. Another object of the invention is to increase the ease with which a carton can be stripped from a forming mandrel. Yet another object of the invention is to increase the production rate of a carton forming machine employing a plurality of mandrels on a turret. Other objects, aspects and advantages of the invention will be apparent from a study of the specification, the drawings and the appended claims to the invention.

In the drawings, FIG. 1 is a front elevational view of a carton forming, filling and sealing machine embodying the present invention;

FIG. 2 is a simplified elevational view of the turret structure of the machine of FIG. 1; and

FIG. 3 is an exploded view in perspective, partly in cross section of a mandrel structure suitable for use in the machine of FIG. 1.

Referring now to the drawings in detail and to FIG. 1 in particular, the carton forming, filling and sealing machine comprises a forming section 11 and a filling and sealing section 12. The forming section 11 com prises a sidewall blank feeding and heating subsection 13, a bottom blank feeding and heating subsection 14, a forming subsection 15, and a transfer subsection 16. The filling and sealing section has two parallel endless conveyor systems 17, and each conveyor system comprises a filling subsection 18 occupying five conveyor stations, a defoaming station 19, a score breaking station 20, a top heating station 21, a folding and sealing station 22, a secondary sealing station 23, a branding station 24, and a transfer station 25.

The sidewall blanks 31 manually placed in the sidewall blank magazine 32 are flat, single sheets of paperboard, rectangular in shape, scored to provide five longitudinal panels, and a gabletop structure, and coated on both the top and bottom surfaces of each sheet with a thermoplastic material, e.g., polyethylene. The sidewall blanks are successively withdrawn from magazine 32 and individually advanced in a step-wise fashion through the sidewall blank heating station 33 to the sidewall blank receiving station 34 for turret 35. At the sidewall blank heating station 33, the side margins to be overlapped and the bottom margin of the sidewall blank are heated to a bonding temperature for the thermoplastic coating.

The turret 35 is joumalled on a horizontal axis and carries eight circumferentiallly spaced apart mandrels 36 extending radially from the axis of turret 35. The cross section of each of mandrels 36 in a plane perpendicular to its longitudinal axis is generally rectangular. Suitable drive mechanism is provided for indexing or effecting intermittent rotation of the turret 35 to move each mandrel from the sidewall blank receiving station 34 through a blank folding station 37; a bottom end closure forming, applying and sealing station 38; a secondary bottom sealing station 39; a stripping station 40; and three successive nonoperating stations 41, 42 and 43.

The tubular carton body having a bottom closure sealed thereto is removed from the mandrel 36 at the stripping station 40 and is transferred to a conveyor pocket 45 of one of the two conveyor systems 17. The product to be packaged is introduced into the opentopped tubular carton in the filling subsection 18. If desired, any foam resulting from the filling operation can be removed at defoaming station 19. The scores for the gable-top structure can be initially folded in the score breaking station 20, resulting in the conventional sixsided top structure. The gable-top ridge panels of the carton are heated in station 21 to a temperature at least as high as the thermal bonding temperature of the thermoplastic coatings on the carton. The heated superstructure is then folded into contact under pressure at the folding and sealing station 22 to effect the bonding of adjacent ridge panels. Secondary sealing station 23 applies pressure to the ridge panels during cooling of the thermoplastic bond. If desired, a date indicia, plant identification or other information can be applied to the bonded ridge panels of the sealed carton at branding station 24. The formed, filled and sealed carton is removed from its conveyor pocket 45 at the transfer station 25 and placed on a delivery conveyor 46. The conveyor systems 17 are intermittently actuated to move conveyor pockets 45 from station to station in a step-wise fashion, while delivery conveyor 46 is operated continuously.

Referring now to FIG. 2, the turret mechanism is illustrated in simplified form. In the sidewall blank re ceiving station 34, the blank 31 is fed into the space between mandrel 36 and the associated clamp arm 51. The clamp arm 51 is then actuated to secure the blank 31 against the mandrel 36. At the station 37, a folding mechanism (not shown) is actuated to fold the blank 31 about the mandrel 36 and to overlap and seal the free edges to form a tubular body 52. At station 38, a heated bottom blank is positioned over the outer end of the respective mandrel 36 with the margins of the bottom blank extending laterally beyond the tubular body 52. A mechanism 53 folds the overhanging margins downwardly and then inwardly into contact with the sides of the tubular body 52 to form a carton having a bottom 54 bonded to the tubular body 52.

Pressure is applied to the bonded areas of bottom 34 at station 39 to maintain the bond while permitting the thermoplastic material to cool to its solidification temperature. The formed carton is stripped from the mandrel 36 at station 40 by suitable means. Details of a suitable construction of the turret mechanism, its drive mechanism, and the mechanisms for stations 34, 37, 38, 39 and 40 are disclosed in Alfred A. Barnes and Harvey H. Klein, US. Pat. No. 2,726,583, issued Dec. 13, 1955, which is incorporated herein in its entirety by reference.

Referring now to FIG. 3, the mandrel 36 comprises a base plate 61, a hollow mandrel body 62 and an end cap 63. The base plate 61 has a mounting ring 64 formed thereon which conforms to the opening 65 in the inner end of hollow mandrel body 62. The outer end face of mandrel body 62 is provided with generally rectangular recess 66, a cylindrical recess 67 and a bolt hole 68. The end cap 63 is provided with a generally rectangular projection 69 on the inner face with a with a secondary cylindrical projection 71 extending from generally rectangular projection 69. Projections 69 and 71 generally correspond to and fit within recesses 66 and 67, respectively, to prevent rotation of end cap 63 with respect to mandrel body 62. A bolt, not shown, extends from base plate 61 through hole 68 into the threaded opening 72 in end cap 63 to secure the end cap 63, mandrel body 62 and base plate 61 together.

Mandrel body 62 has four side faces 73, 74, and 76, and end cap 63 has four corresponding side faces 77, 78, 79 and 80. When the sidewall blank 31 is positioned in station 34, the trailing (bottom) edge of the blank 31 is even with the end face of cap 63. Thus the combination of side faces 73 and 77, 74 and 78, 75 and 79, and 76 and 80 constitute the four forming surfaces of mandrel 36 for the tubular body 52. The thickness of end cap 63 is at least as great as the width of the margin of the bottom blank which is folded in overlapping relationship with the tubular body 52 so that end cap 63 serves as the anvil for the bonding operation of mechanism 53. Grooves 81 and 82 are provided in side faces .73 and 75 and extend the full length of mandrel body' 62. Openings 83 and 84 in end cap'63 provided fluid communication between the end face of end cap 63 and grooves 81 and 82, respectively, so that during the removal of the carton 50 from the mandrel 36 air enters the space between the end face of cap 63 and the bottom 54 by way of grooves 81 and 82 and passageways 83 and 84. Base plate 61 is provided with bolt holes 85 for the securing of the mandrel assembly to the turret base.

In accordance with the present invention, the mandrel body 62 has a metal base with the side faces 73, 74, 75 and 76 thereof being coated with a layer 91 of a normally solid poly(arylene sulfide). Any normally solid poly(arylene sulfide) can be used in the practice of this invention. The term poly(arylene sulfide) is meant to include not only homopolymers but also arylene sulfide copolymers, terpolymers, and the like, as well as blends of two or more such polymers. Poly(arylene sulfides) which are particularly suited for use in this invention are those having inherent viscosities in chloronaphthalene (0.2 gram polymer in cc chloronaphthalene) at 206C of at least about 0.08, preferably between about 0.1 and about 0.3, and more preferably between about 0.13 and about 0.23. Examples of suitable polymers are disclosed, for instance, in Edmonds et al. US. Pat. No. 3,354,129, Nov. 21, 1967. The presently preferred polymer is poly(phenylene sulfide) made as in Example I in US. Pat. No. 3,354,129. Other examples of poly(arylene sulfides) are poly(4,4'- biphenylene sulfide); poly(2,4-tolylene sulfide); a copolymer from p-dichlorobenzene, 2,4-dichlorotoluene, and sodium sulfide; and blends thereof.

In addition, the poly(arylene sulfide) can be blended with other polymers, conventional additives, fillers, extenders, pigments, stabilizers, and the like. Especially preferred fillers are TiO Fe O and fluorocarbon polymers such as polytetrafluoroethylene. Up to about parts by weight, either singly or in combination, of such fillers may be used per 100 parts by weight of poly( arylene sulfide), about 5 to about 80 parts by weight being presently preferred.

In a presently preferred embodiment of the invention, titanium dioxide is mixed with the poly(arylene sulfide) at a concentration within the range of about 0.5 percent to about 100 percent by weight of titanium dioxide based on the weight of poly(arylene sulfide). More preferably, the concentration of titanium dioxide will be within the range of about 10 to about 50 weight percent based on the weight of poly(arylene sulfide). The preferred embodiment also contains from about 0.5 percent to about 75 percent by weight of a fluorocarbon polymer based on the weight of the poly(arylene sulfide). A preferred fluorocarbon polymer is polytetrafluoroethylene, and the preferred concentration thereof is in the range of about 5 to about 35 percent by weight of the poly(arylene sulfide).

The coating composition can also contain from about 0.3 percent to about 4 percent by weight of a siliceous material having a particle size of less than 10 microns, preferably less than 5 microns, and more preferably less than 2 microns, including silica; silicates such as calcium silicate and magnesium silicate; aluminosilicates including artificial zeolites and clays such as bentonite, illite, montmorillanite, kaolinite, attapulgite, and talc; and combinations of these. Concentrations substantially in excess of about 4 percent by weight based on poly(arylene sulfide) have a deleterious effect on the bonding strength of the resultant coating. A siliceous material concentration within the range of about 0.4 percent to about 2 percent by weight based on the weight of poly(arylene sulfide) is presently preferred, with a concentration in the range of about 0.5 to about 1 percent by weight based on the weight of poly(arylene sulfide) being more preferred.

The substrate to be coated can be prepared by degreasing, cleaning, and drying the surface to be coated. Cleaning can be accomplished by washing o-r wiping with trichloroethylene, acetone, or other similar cleaners or solvents, then air drying, wiping the surface dry, or otherwise drying the surface by any suitable method.

While the poly(arylene sulfide) coating can be ap plied to the substrate in any manner known to the art, a preferred method is to prepare a slurry containing the poly(arylene sulfide) based coating composition, and then to spray coat the substrate with the slurry. Such a spray coating method is conducive to application of a coating of uniform thickness having a smooth, unbroken surface.

When a slurry is employed, any liquid can be used as the diluent provided the liquid is inert to the other components of the slurry and to the substrate, and provided it is readily volatilized prior to or during the subsequent heating or curing treatment. Suitable liquids include water; light hydrocarbons having-5 to 8 carbon atoms, such as hexane, isooctane, and pentane; benzene; toluene; petroleum ether; alcohols or glycols having l to '4 carbon atoms, such as ethanol, propanol, i-propanol, ethylene glycol, butanol-l, and propylene glycol; or mixtures thereof. A wetting agent, usually a nonjonic material such as alkylphenoxypolyethoxy alcohol, in the proportion of about 0.5 'percent ot about 1 percent by weight based on water can be used. Other suitable wetting agents are octylphenoxypolyethoxyethanol, aliphatic polyethers, nonylphenylpolyethylene glycol ether, and trimethylnonylpolyethylene glycol ether. A mixture of water and propylene glycol is presently preferred. Use of a diluent containing 60 volume percent water and 40 volume percent propylene glycol has yielded excellent results. A high ratio of glycol to water prevents premature volatilization of the diluent so that boundaries can be clearly delineated and overspraying can be avoided or minimized by the ready coalescence of boundary areas.

Preparation of a suitable slurry can be accomplished in any manner known to the art. It has been found that a suitable slurry can be obtained by ball milling the poly(arylene sulfide), siliceous material, other additives, and diluent for a period of time within the range of about 2 to about 48 hours. The concentration of the polymer in the carrier liquid depends upon the particular method of coating application and whether or not additional solids are employed. As a practical matter, the slurry should not be so dilute that the polymer particles are not closely enough associated to permit them to fuse together on melting. On the other hand, the thickness of the slurry and its ease of application will impose a practical upper limit on the solids concentration. Generally, a solids content within the range of about to about 60 weight percent can be used, and best results are obtained with a slurry that contains about 25 to about 40 weight percent solids based on the weight of the total slurry.

The slurry is preferably sprayed onto the substrate without prior heat treatment of the substrate, but the substrate may be heated to a temperature of at least 400F, more preferably between about 600 and about 800F, prior to application of the coating. If the substrate is heated prior to slurry application, it is preferably maintained at a temperature high enough to fuse the polymer on contact during the coating operation.

After the coating has been applied, the coating is cured by heating at a temperature in the range of about 500F to about 900F, in an oxygen-containing atmosphere, such as air, for a time in the range of about 5 rinsed with solvent, and the excess solvent was evaporated. The cleaned metal base 90 was heated to-about 700F and then was sprayed, while hot, with a slurry formed by admixing 800 grams of pol-y(phenylene sulfide), 264 grams of titanium" dioxide, 19 grams of bentoni'te, 16 grams of octylphenoxypolyethoxy ethanol, 1657 grams of water and 1105 grams of propylene glycol. The coated base was cured in an oven for 60minutes at 700 to 750F After cooling, the'side faces and the outer portion of the end of the coated base was spray coated with a slurry formed by admixing 800 grams of poly(p'henylen'e sulfide),200 grams-of titanium'dioxide, 150 grai'ns of polytetrafluoroethylene,

minutes to about 12 hours or more. The thickness of 3200 milliliters of a 50150 mixture 'of propylene glycol andwatei", and 32"grams of octylphenoxypolyethoxy 'ethanohThe thus coated base was heated at'700750F for 60 minutes to cure the secorid coating.

In the embodiment illustrated in FIG. 3, the metal base 90 is formed of aluminum and is fabricated in a hollow configuration to reduce the weight of the mandrel. This is particularly important for high speed operation of turret 35 where the mandrel weight is a significant factor in the stresses imposed on the machine by the intermittent rotation of turret 35 as well as the power required to initiate and terminate the rotation.

In order to achieve the greater durability of steel for the operation of sealing or bonding the bottom blank to the outer margin of the tubular body 52, the end cap 63 can be made of steel. The side faces 77, 78, 79 and 80 can be polished to reduce the frictional resistance offered by the steel end cap to the stripping of the container 50 from the mandrel 36. Although the end cap 63 can also be coated with the poly(phenylene sulfide) coating composition, satisfactory results have been achieved with only faces 73, 74, and 76, representing a major portion of the blank contacting surface, being coated.

Reasonable variations and modifications are possible within the scope of the foregoing disclosure, the draw ings and the appended claims to the invention. For example the coated mandrel of the invention can be used with other cross-sectional configurations, such as circular, oval, rectangular, triangular, and the like, and can be tapered such as for forming frustoconical convolutes. The mandrels can be employed on other types of turrets, for example the mandrels can be positioned vertically on the periphery of a horizontal turret so that the axes of the mandrels are parallel to the axis of rotation for the turret. The formation of the bottom 54 can be omitted where a bottomless convolute is desired, such as for making mailing tubes or megaphones.

What is claimed is: g

1. In a machine for forming a tubular container wherein a sidewall blank is wrapped around a mandrel with the opposite side edges overlapping and the overlapping portions are bonded to form a convolute, and a bottom closure is formed on one end of said convolute, comprising a turret, a plurality of said mandrels positioned therein, and means for rotating said turret to move each of said mandrels sequentially through a sidewall blank receiving station, a sidewall blank folding and bonding station, a bottom closure forming station, and a stripping station for the removal of the thus formed container from the respective mandrel; the improvement comprising each of said mandrels having a hollow mandrel body formed of aluminum with the blank contacting surface of said mandrel body being coated with a coating composition containing 21 normally solid poly( arylene sulfide), thereby reducing the frictional resistance between each mandrel and the respective convolute and reducing the weight of each mandrel, permitting the attainment of a higher production rate for .the machine, and each of said mandrels having an end cap formed for steel and positioned on one end of the mandrel to serve as an anvil in the formation of the bottom closure.

2. A machine in accordance with claim 1 wherein said mandrels are positioned on said turret with the elongated axis of each mandrel being in a plane perpendicular to the axis of rotation of said turret and extending radially with respect to said axis of rotation.

3. A machine in accordance with claim 2 wherein said coating composition comprises a normally solid poly( arylene sulfide), from about 0.5 to about 100 percent by weight titanium dioxide, based on the weight of poly(arylene sulfide), and from about 0.5 to about 75 percent by weight, fluorocarbon polymer based on the weight of poly(arylene sulfide).

4. A machine in accordance with claim 3 wherein said poly(arylene sulfide) is poly(phenylene sulfide).

5. A machine in accordance with claim 1 wherein said coating composition comprises a normally solid poly(arylene sulfide), from about 0.5 to about 100 percent by weight titanium dioxide, based on the weight of poly(arylene sulfide), and from about 0.5 to about 75 percent by weight, fluorocarbon polymer based on the weight of poly( arylene sulfide).

6. A machine in accordance with claim 1 wherein said poly(arylene sulfide) is poly(phenylene sulfide).

7. A machine in accordance with claim 6 wherein all of the blank contacting surface of said mandrel is coated with said coating composition. 

1. In a machine for forming a tubular container wherein a sidewall blank is wrapped around a mandrel with the opposite side edges overlapping and the overlapping portions are bonded to form a convolute, and a bottom closure is formed on one end of said convolute, comprising a turret, a plurality of said mandrels positioned therein, and means for rotating said turret to move each of said mandrels sequentially through a sidewall blank receiving station, a sidewall blank folding and bonding station, a bottom closure forming station, and a stripping station for the removal of the thus formed container from the respective mandrel; the improvement comprising each of said mandrels having a hollow mandrel body formed of aluminum with the blank contacting surface of said mandrel body being coated with a coating composition containing a normally solid poly(arylene sulfide), thereby reducing the frictional resistance between each mandrel and the respective convolute and reducing the weight of each mandrel, permitting the attainment of a higher production rate for the machine, and each of said mandrels having an end cap formed for steel and positioned on one end of the mandrel to serve as an anvil in the formation of the bottom closure.
 2. A machine in accordance with claim 1 wherein said mandrels are positioned on said turret with the elongated axis of each mandrel being in a plane perpendicular to the axis of rotation of said turret and extending radially with respect to said axis of rotation.
 3. A machine in accordance with claim 2 wherein said coating composition comprises a normally solid poly(arylene sulfide), from about 0.5 to about 100 percent by weight titanium dioxide, based on the weight of poly(arylene sulfide), and from about 0.5 to about 75 percent by weight, fluorocarbon polymer based on the weight of poly(arylene sulfide).
 4. A machine in accordance with claim 3 wherein said poly(arylene sulfide) is polY(phenylene sulfide).
 5. A machine in accordance with claim 1 wherein said coating composition comprises a normally solid poly(arylene sulfide), from about 0.5 to about 100 percent by weight titanium dioxide, based on the weight of poly(arylene sulfide), and from about 0.5 to about 75 percent by weight, fluorocarbon polymer based on the weight of poly(arylene sulfide).
 6. A machine in accordance with claim 1 wherein said poly(arylene sulfide) is poly(phenylene sulfide).
 7. A machine in accordance with claim 6 wherein all of the blank contacting surface of said mandrel is coated with said coating composition. 